Means for and method of duplicating



Sept- 30, 1941. w. HosKlNs, JR A 2,257,116 yMEANS FR AND METHOD'OF DUPLICTING File`d Dec. 20, 19?'9 Patented Sept. 30, 1941 MEANS Foa AND METHOD oF D UPLICATING William Hoskins, Jr., La Grange, Ill., as signor to Ditto, Incorporated, Chicago, Ill., a corporation of West Virginia Application December 20, 1939, Serial No. 310,108

Claims.

The invention relates to means for and methods of duplicating.

One embodiment of the invention is a hectograph blanket in which the copying mass contains a dispersion of a water insoluble substance. I have discovered that the incorporation of minute particles or droplets of a water insoluble substance such as oil in a hectograph copy mass results in a hectograph blanket which gives extremely bright copies, and which at the same time is tough, elastic and resistant to heat and humidity changes as well as to mechanical friction and abrasion. Likewise good adhesion of the copying composition to the backing is attained.

Other objects and advantages of the invention Will become apparent as the following detailed description progresses, reference being had to the accompanying drawing, whereinv Fig. 1 is a sectional elevation of a hectograph pad constituting a preferred embodiment of this invention, and

Fig. 2 is a sectional elevation of a modified hectograph pad.

In Fig. 1 of the drawing, the reference character I designates a gelatinous composition containing droplets of oil secured to a backing 3 of paper, cloth or other suitable material by means of a bonding layer, 2 which may be any of the usual compositions such as linseed oil, fish oil or the like commonly used to obtain increased adhesion of the copying composition to the backing.

The bonding layer is not essential and may be eliminated with however less satisfactory results. This modification is shown in Fig. 2, wherein the reference numeral I represents the gelatin composition containing the oil securedv directly to the backing 3.

The copy mass embodied in the present invention comprises a gelling agent such as glue or gelatin, a water soluble softener such as glycerine,

invert sugar, sodium lactate; a hardener such as chrom alum or other protein precipitant; water, and a mineral oil or other inert water insoluble material capable of dispersion with the other ingredients.

The water insoluble materials contemplated include the waxes, fats, and oils. These materials are dispersed in the copy mass as droplets or particles ofmicroscopic or colloidal size.

Among the waxes contemplated are paraffin materials coming under the broad definition of oil such as glycol stearate and glycol oleate.

The oil or oil like material which it ispreferre'd to employ is one of the so-called solubilized or self-emulsifying oils. Such oils are oils generally of the paraflin type, which contain la strong emulsifying agent, usually a sulfonated naphthenate.

To illustrate the invention, the following formulae of suitable hectograph composition are given:

Parts by weight Glycerin Invert sugar. Sodium lactate. Sodium citr Petrolatum Castor oil Chrome alum l Superia Oil is the trade name of a readily 'cmulsiilable product comprising paraffin oil, and a sulphonated napthenate as emulsifying agent. This product is being sold by the Standard Oil Company ol Indiana.

The ingredients are mixed together and heated in a' water bath with stirring. The dispersion so formed is coated on the backing and allowed to gel, forming the hectograph pad. The gelled hectograph mass will be found to contain the inert oleaginous material in a highly dispersed state. There is substantially colloidal distribution of the oleaginous material in the hectograph mass ir the form of an oil in water emulsion.

Copies are prepared from the hectograph pad of the invention in the usual manner. A design is formed on a copy paper by writing or typing' with an ink made of water or alcohol soluble dyes. The design is then contacted with the gelatinous copy surface of the pad, whereupon the dye is largely transferred to the composition giving the design in mirror reverse. Copies are then made by contacting sheets of paper with the design on the hectograph copy mass. It will be found that a large number of copies of high color intensity 5 tween the dispersed water insoluble particles and thecontinuous phase of the hydrophilic composition. Therefore, the dye will be retained on or near the surface of the composition thus being more readily available for copying purposes than would otherwise be the case.

While I have shown and described certain embodiments of my invention, it is to be understood that it is capable of many modications. Substitution of equivalent materials and changes in the proportions may be made without departing from the spirit and scope oi.' the invention as described inthe appended claims, in which it is my intention to claim all novelty inherent in my invention as broadly as possible, in view of the prior art.

I claim:

l. A hectograph blanket comprising a backing having thereon a copy mass of a hydrophilic gel containing oildispersed in the copy mass in the (um oi' minute globules.

2. A hectograph blanket comprising a backing having thereon a copy mass of a hydrophilic gel containing oil dispersed in the copy mass as an oil in water type emulsion.

3. A hectograph blanket comprising a backing 25 having thereon a copy mass comprising a gelatinous material, a water soluble softener, water. an emulsifying -agent and droplets of oil oi' not more than microscopic size uniformly dispersed in the copy mass.

4. 'I'he method of producing copies of high color intensity which comprises contacting a sheet having a design of water soluble dye with a gelatinous copy mass containing minute par-l ticles of a water insoluble substance whereupon the design in reverse remains on the composition, contacting the design on the duplicating composition with a copy sheet to transfer the design tothe copy sheet. Y

5. The method of producing copies of high color intensity which comprises contacting a sheet having a design of water soluble dye with a gelatinous copy mass containing an oil and water type emulsion whereupon the design in' reverse remains on the composition, contacting the design on the duplicating composition with a copy sheet to transfer the design to the copy sheet WILLIAM HOSKINS, Jn. 

